Mine roof support

ABSTRACT

A mine roof support comprises a base structure, extensible prop means mounted on said base structure and a roof-engaging structure mounted on said prop means. The roof-engaging structure includes a canopy of U-shape or having a U-shaped part and a roof-engaging bar or member positioned or having a part positioned between or partially between the limbs of said Ushaped canopy or U-shaped part thereof. In one preferred embodiment of the invention the canopy is supported on at least one front prop and on at least one rear prop and the roofengaging bar or member is pivotally connected to the canopy by a pivot having its axis positioned between said front and rear props.

United States Patent Pollard Mar. 7, 1972 [54] MINE ROOF SUPPORT 3,425,229 2/1969 Groetschel ..61/45 1) [72] Inventor: Thomas Pollard, Chofley, England 3,490,243 1/1970 Groetschel ..61/45 1) 73 Assignee: Gullick Limited, Wigan, Lancashire, En- FOREIGN PATENTS 0R APPUCATIONS gland 969,940 9/1964 Great Britain ..61/45 22 F] d: Se L 16 19 9 1,004,110 9/1965 Great Britain..... ...6l/45 I 1 1,091,602 11/1967 Great Britain ..61/45 [21] App1.No.: 858,379

Primary Examiner-Dennis L. Taylor [30] Foreign Application Priority Dam Attorney-Bennan, Davldson and Berrnan Oct. 1, 1968 Great Britain ..46,434/68 [57] ABSTRACT 52] US. Cl. ..61/45 1), 248/357 A mine P a base extensible [5 n Int Cl I E21 d 15/44 prop means mounted on said base structure and a roof-engag- [58] Field 61 Search ..61/45.2; 299/31, 33; 248/357; mumed Said Pmp meansstructure 1ncludes a canopy of U-shape or having a U-shaped 91/170 MP part and a roof-engaging bar or member positioned or having a part positioned between or partially between the limbs of sai -s ape canopy or -s pe part ereo 11 one [56] References Cited U h d U ha d th f l UNITED STATES PATENTS preferred embodiment of the invention the canopy is supported on at least one front prop and on at least one rear prop 2,910,281 10/1959 wilkenloh et a1 ..61/45 d h rooflengaging b or member is pivotally connected to 3,197,966 8/1965 Arno the canopy by a pivot having its axis positioned between said 3,333,426 8/1967 Jackson from and rear props 3,365,893 1/1968 Allen 3,381,480 5/1968 Andrews ..61/45 2 Claims, 4 Drawing Figures l 1 1 1 I j l A 18 2O--1: v17

l I I l 13 i 16 Y I l Y l l 1 MINE noor SUPPORT This invention is for improvements in or relating to mine roof supports. The invention is particularly concerned with self-advancing or powered mine roof supports.

A powered or self-advancing mine roof support generally comprises a plurality of hydraulically extensible props or legs assembled in or on a base structure and supporting at their upper parts a roof-engaging structure which, when the legs or props are extended, is applied to the roof for the support thereof. The roof'engaging structure may comprise a canopy supported on a plurality of the props or legs and a roof-engaging bar or beam pivotally connected to the canopy and supported on one or more of the props or legs. The base structure usually also houses a horizontally disposed double-acting ram means. This rarn means serves to pushover a face conveyor towards the mineral face, as winning of the coal or other mineral proceeds, and then, by anchoring the ram means to the conveyor and retracting it, the support is advanced up to the conveyor after the props or legs have been temporarily lowered to release the roof-engaging structure from the roof.

According to the present invention there is provided a mine roof support having a roof-engaging structure comprising a canopy of U-shape or having a U-shaped part and a roofenagaging bar or member positioned or having a part positioned between or partially between the limbs of said U- shaped canopy or U-shaped part thereof.

According to a further feature of the invention there is provided a mine roof support having a roof-engaging structure comprising a canopy of U-shape or having a U-shaped part and a roof-engaging bar or member pivotally connected to said canopy and located or having a part located between the limbs of said U-shaped canopy or U-shaped part thereof.

Conveniently the roof-engaging bar or member extends forwardly of the canopy, preferably by a substantial amount. It may, for example, be in the form of a cantilever.

The invention will be further described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of one embodiment,

FIG. 2 is a plan view of the embodiment shown in FIG. 1,

FIG. 3 is a side elevation of a second embodiment, and

FIG. 4 is a plan view of the embodiment shown in FIG. 3.

In the drawings only the parts of the support relevant to the present invention are shown. The support will, of course, comprise other pans such as an advancing ram. These can be in accordance with known constructions.

Referring to FIGS. 1 and 2 of the drawings, the support comprises a rear base structure and a forward base part 1 1. The base structure 10 and the base part 11 are connected together by link or tie-bar means indicated at 12. This link or tie-bar means may be constructed and arranged as described in the US. Pat. Nos. 3,197,966 or 3,383,867.

Mounted in the base structure 10 are four hydraulically extensible props or legs 13, 14, 15 and 16. The mountings for these props or legs may be in the form of concave/convex seatings or the like which allow for some limited tilting movement of the props relatively to the base structure. A single hydraulically extensible leg or prop 17 is similarly mounted on the forward base part 1 l.

A U-shaped canopy 18 is supported on the upper parts of the props I3, 14, 15 and 16. Here again, the mountings for mounting the canopy on the upper parts of the props may include convex-concave seatings or the like to provide for limited angular movement between the canopy and the props to take care of, for example, roof convergence.

The roof-engaging structure of the support also comprises a roof-engaging bar or cantilever 19 which is pivotally connected to the canopy 18 as indicated at 20. It will be noted that a substantial part of the length of the bar 19 at its rear is positioned between the limbs 18a and 18b of the U-shaped canopy, and that the axis of the pivot 20 is between the front legs 15, 16 and the rear legs 13, 14 which support the canopy 18. The roof-bar 19 is seated, by means of a concave/convex seating arran ement, on the single prop 17.

The embo ment of the invention shown in FIGS. 3 and 4 is similar to that just described with reference to FIGS. 1 and 2 and where applicable like reference numerals have been used to designate like parts.

In the embodiment shown in FIGS. 3 and 4, however, the

two-part base structure 10, 11 is replaced by a single rigid base structure 21. Furthermore, the U-shaped canopy is somewhat larger and, in particular, its limbs 18a and 18b have been extended so as to bring the props 15 and 16 on which the canopy is partially supported into line with the prop 17 which supports the roof-bar 19.

ln'the above-described arrangements of the roofengaging structure the side-by-side positioning of the limbs 18a and 18b, of the canopy, and the roof-bar 19 enable these members to assist each other in properly supporting the roof and in particular help towards achieving an even distribution of the load on the support. This, at least in part, results from the fact that the rear part of the mo -engaging bar 19 cannot be depressed below the limbs 18a and 18b of the canopy so that an excessive load is put on said limbs. Furthen'nore, the construction allows the props or legs 13, 14, 15, 16 and 17 to be arranged to obtain the best possible loading and load-distribution conditions.

Although the roof-engaging bar has been more particularly described as being pivotally attached to the canopy it is not necessarily attached thereto. It could, for example, be positioned between the limbs of the canopy on one or more hydraulic props upstanding from the base structure of the support.

Furthermore, the roof-engaging member 19 is not necessarily a straight bar. It could, for example, be a T-shaped member having its stem positioned between the limbs of the U-shaped canopy.

I claim:

1. A mine roof support comprising a base structure, rearwardly positioned prop means, forwardly positioned prop means and intermediate prop means between said rearwardly positioned and forwardly positioned prop 'means, all said props means being mounted on said base structure, a roof-engaging canopy of U-shape or having a U-shaped part supported on said rearwardly positioned and said intermediate prop means, a roof-engaging bar or member having a part positioned between rigid limbs of said U-shaped canopy or U- shaped part thereof and extending forwardly of said canopy by a substantial amount and supported on the forward prop means, and pivot-pin means passing through said roof'engaging bar or member and said rigid limbs of the U-shaped canopy or U-shaped part thereof at a position between the rearwardly position prop means and the intermediate prop means thereby pivotally to connect the roof-engaging bar or member to the canopy.

2. A mine roof support as claimed in claim 1 wherein said pivot-pin means is substantially midway between the rearwardly positioned prop means and the intermediate prop means. 

1. A mine roof support comprising a base structure, rearwardly positioned prop means, forwardly positioned prop means and intermediate prop means between said rearwardly positioned and forwardly positioned prop means, all said props means being mounted on said base structure, a roof-engaging canopy of U-shape or having a U-shaped part supported on said rearwardly positioned and said intermediate prop means, a roof-engaging bar or member having a part positioned between rigid limbs of said U-shaped canopy or U-shaped part Thereof and extending forwardly of said canopy by a substantial amount and supported on the forward prop means, and pivot-pin means passing through said roof-engaging bar or member and said rigid limbs of the U-shaped canopy or U-shaped part thereof at a position between the rearwardly position prop means and the intermediate prop means thereby pivotally to connect the roof-engaging bar or member to the canopy.
 2. A mine roof support as claimed in claim 1 wherein said pivot-pin means is substantially midway between the rearwardly positioned prop means and the intermediate prop means. 